1. Field of the Invention
The present invention relates to a light source device, a projection apparatus, and a projection method that are suitable for a Digital Light Processing (DLP [registered trademark]) data projector apparatus and the like.
2. Description of the Related Art
Displaying colors with a projection display apparatus requires planar light sources that emit the primary colors of red, green, and blue, and spatial optical modulators corresponding to the primary colors. Therefore, the increase in the number of parts hinders reduction in the size, weight, or cost of the entire device. For example, Jpn. Pat. Appin. KOKAI Publication No. 2004-341105 discloses the technology in which a light-emitting diode that emits ultraviolet light is used as a light source and the ultraviolet light is emitted to a color wheel, thereby producing visible light corresponding to red, green, and blue. Specifically, a visible light reflection film that transmits ultraviolet light and reflects visible light is formed on the light source side of the color wheel, and a phosphor layer that emits visible light corresponding to red, green, and blue by being illuminated with ultraviolet light is formed on the back of the color wheel.
However, when the invention described in Jpn. Pat. Appin. KOKAI Publication No. 2004-341105 mentioned above is adopted, the presently known various red phosphors are significantly lower in light emission efficiency, compared to green and blue phosphors, resulting in inadequate red luminance.
When a brighter projected image is formed by giving priority to luminance, white balance is lost, with the result that color reproducibility degrades. Conversely, giving priority to white balance and hence color reproducibility decreases the overall luminance of a projected image because of the low luminance of the red image, resulting in a dark image.
The present invention has been made in view of the foregoing problems of conventional technologies. It is accordingly an object of the present invention to provide a light source device, a projection apparatus, and a projection method, which convert light from a light source into a plurality of colors by using, e.g., a color wheel, use another light source, and stabilize drive while taking into account the light emission characteristics of each of the light sources, thereby making color reproducibility compatible with the brightness of a projected image.